Vehicle and charging control method of the vehicle

Technical field of vehicle and charging control method of the vehicle

[0001] The present invention relates to a vehicle capable of efficiently performing scheduled charging and a charging control method of the vehicle.

Background technique

[0002] Hybrid electric vehicles (HEVs) have attracted considerable attention as environmentally friendly vehicles. Hybrid vehicles generally refer to vehicles that use two power sources. The two power sources can include an engine and an electric motor. Compared with vehicles with only internal combustion engines, such hybrid vehicles have good mileage and power performance, and can also reduce emissions. Therefore, many hybrid vehicles have been developed.

[0003] In hybrid vehicles, a plug-in hybrid electric vehicle (PHEV) can be plugged in to charge a battery that drives a motor with external electricity.

[0004] In addition, electric vehicles (EV) as another environmentally friendly vehicle have also attracted considerable attention. Since electric vehicles are usually driven by only electric motors, the batteries driving the electric motors need to be charged.

[0005] Taking into account the convenience of the user's travel time, such an EV or PHEV has a scheduled charging function that automatically charges the battery when the vehicle is not in use, and when electric power is available late at night and/or when the cost is low.

[0006] However, even if the scheduled charging function is used when the electricity price is available in the middle of the night considering the departure time, the battery may still not be fully charged according to external conditions or devices (for example, when 110V and 220V input voltages are mixed). Electricity situation. The charging logic can vary with the type of charger (for example, cable control box (ICCB) and EV power supply equipment (EVSE)), which will cause confusion for the driver.

Summary of the invention

[0007] Therefore, the present invention relates to a vehicle and a charging control method thereof, which can basically avoid one or more problems caused by the limitations and defects of the prior art.

[0008] An object of the present invention is to provide a vehicle that more effectively provides a scheduled charging function, and a charging control method thereof.

[0009] Another object of the present invention is to provide a vehicle that can provide an optimal scheduled charging function in consideration of the actual charging environment, and a charging control method thereof.

[0010] Other advantages, objectives and features of the present invention will be partly proposed in the following description, and when examined below, for those of ordinary skill in the art, it will become apparent to a certain extent, or may be Learned from the implementation of the present invention. The above objectives and other advantages of the present invention can be realized and obtained by the specific structure indicated in the written description, its claims and the accompanying drawings.

[0011] As implemented and generally described herein, in order to achieve these goals and other advantages, and in accordance with the goals of the present invention, a charging control method for a vehicle including an electric motor and a battery for driving the electric motor may include: setting a reservation Charge; close the first switch in the on-board charger (OBC) controller; when the first switch is closed, when the external charger is supplying power, measure the input voltage on the input side of the OBC controller; set based on the measured input voltage Charging start time; and, when the charging start time is reached, start charging the battery

[0012] According to another aspect of the present invention, the present invention provides a vehicle including: an electric motor for driving the vehicle

Wheel; battery, which supplies power to the motor; and, the on-board charger (OBC) controller, when the scheduled charging is set, it closes the first switch, when the external charger supplies power, the input voltage is measured on its input side, based on the measurement Set the charging start time of the input voltage, and when the charging start time is reached, the battery charging starts.

[0013] At least one embodiment of the present invention includes the following effects:

[0014] In the vehicle, more efficient scheduled charging can be performed.

[0015] Specifically, when the scheduled charging function is used, since the estimated charging time is calculated by actual voltage measurement when the actual charging is not performed, the life of the charger can be increased, and the application of cheap electricity prices can be best used time.

[0016] The aspects of the present invention are merely embodiments of the present invention, and various embodiments can be designed based on the technical features of the present invention, and they can be understood by those of ordinary skill in the art based on the detailed description of the present invention.

Description of the drawings

[0017] The drawings included to provide a further understanding of the present invention, and included in the present application and constituting a part of the present application, show embodiments of the present invention, and together with the description serve to explain the present invention The role of principle. In the attached picture:

[0018] FIG. 1 is a view showing an example of a charging system structure of a vehicle according to an exemplary embodiment of the present invention;

[0019] FIG. 2 is a flowchart showing an example of a process of performing a general scheduled charging function according to an embodiment of the present invention;

[0020] FIG. 3 is a flowchart showing an example of an effective charging control process in a vehicle according to an embodiment of the present invention; [0021] FIGS. 4A and 4B are diagrams showing when charging control according to an embodiment of the present invention is applied; In the method, the view of an example of the process of performing charging according to the input voltage;

[0022] FIG. 5 is a flowchart showing an example of an effective charging control process in a vehicle according to another embodiment of the present invention;

[0023] FIG. 6 is a view showing a switch provided on the side of an on-board charger (OBC) applied to another embodiment of the present invention;

[0024] FIG. 7 is a circuit diagram showing a structure of a vehicle side charger according to an embodiment of the present invention, and a method of measuring an input voltage using a switch according to an embodiment of the present invention;

[0025] FIGS. 8A and 8B are views illustrating an input current estimation method according to an embodiment of the present invention;

[0026] FIGS. 9A to 9c are views showing examples of logic for determining an estimated charging time according to an embodiment of the present invention; and

[0027] FIG. 10 is a flowchart showing an example of an effective charging control process in a vehicle according to an embodiment of the present invention.

Detailed ways

[0028] Reference will now be made in detail to the embodiments of the present invention whose examples are shown in the accompanying drawings. In any case, throughout the drawings, the same reference numerals will be used to refer to the same or similar components, and repeated descriptions thereof will be omitted. The suffixes "module" and "unit" of the elements herein are used for convenience of description, so they can be used interchangeably and do not have any different meanings or functions.

[0029] In the process of describing the embodiments of the present invention, if it is determined that detailed descriptions of related known functions or structures unnecessarily obscure the scope of the present invention, the detailed descriptions thereof will be omitted. In addition, the drawings are provided only for better understanding

The embodiments disclosed in this document are not intended to limit the technical concepts disclosed in this document. Therefore, it should be understood that the drawings include all modifications, equivalents, and replacements within the spirit and scope of the present invention.

[0030] In addition, in the present, unless otherwise stated, the term "battery" may refer to a battery that provides power to an electric motor, rather than a 12V battery used to operate electronic devices in a general vehicle.

[0031] Before describing the vehicle charging system according to the embodiment of the present invention, a general vehicle charging system will be described with reference to FIG. 1.

[0032] FIG. 1 is a view showing an example of a general charging system.

[0033] Although FIG. 1 shows a charging system for an electric vehicle (EV) or a plug-in electric vehicle (PEV), the charging system of FIG. 1 may be similarly applied to the engine except for parts related to engines driven by fossil fuels. PHEV.

[0034] Referring to FIG. 1, the charging system 100 of an EV may include: a power line communication (PLC)/electric vehicle communication controller (EVCC) 110, which is used to control fast charging; an on-board charger (OBC) controller 120, which uses To control slow charging; battery management system 130; and battery 140.

[0035] The EVCC, the OBC controller, and the BMS may be connected to each other through a controller area network (CAN) communication. In addition, the charging system 100 may be connected to a charger (electric vehicle power supply device (EVSE)) 200 through a charging connector. The charger 200 can send a pulse width modulation (PWM) signal to the vehicle through the control guide (C/P) line, and the vehicle can determine whether or not it is determined by the duty cycle of the PWM signal (ie, the ratio of the H signal and the L signal of the pulse width) Perform slow charging or fast charging.

[0036] A process of performing ordinary scheduled charging based on the configuration of the above-described system will be described with reference to FIG. 2.

[0037] FIG. 2 is a flowchart showing an example of a process of performing ordinary scheduled charging according to an embodiment of the present invention.

[0038] Referring to FIG. 2, when the driver inputs the departure time and sets a cheap electricity price in order to use late-night power, or an electricity price that is cheaper compared to a more expensive electricity price (S210), the current state of charge of the battery can be considered (SOC), the input departure time, and the variation margin of the maximum charging time depending on the current SOC determine the charging start time of the vehicle. The OBC controller can sleep until the charging start time, and wake up at the charging start time (S220). Here, the wake-up of the OBC controller may mean that the vehicle is switched to the IG-on state.

[0039] The OBC controller may wake up to start charging (S230), and when the charging ends (S240), the vehicle may be switched to an IG off state (S250). If the charge fails to reach the specified target charge level (hereinafter, for convenience, it is assumed to be fully charged), a failure report message can be sent to the specified device, or a failure report procedure can be executed, for example, an error code is output (S260) .

[0040] Here, the departure time and cheap electricity price may be input through a user interface provided in the vehicle using a video-audio-navigation (AVN) system, or may be received from an external device through a charger or a telematics server.

[0041] In the above process, although the margin time is applied according to the SOC, since the charging start time can be determined based on the assumption that the charger's input current and voltage are predetermined values, if the charger's estimated voltage and charging If the actual voltage of the device is different, it will not be fully charged. For example, although the charging start time is set to a later time based on the assumption that the input voltage of the charger is 220V, the actual input voltage of the charger may be 110V, so full charging cannot be completed at the start time. In contrast, although the charging start time is set to an earlier time based on the assumption that the charger's input voltage is 110V, the actual voltage of the charger may be 220V, so charging will start before the electricity price is discounted. Therefore, electricity prices will not be discounted.

[0042] In an embodiment of the present invention, the input voltage of the charger can be assumed to be the minimum value to calculate the charging start time. When charging starts at the charging start time, measure the actual input voltage and current to measure the charging power of the charger. The charging start time can be reset based on the measured charging power of the charger.

[0043] According to an aspect of this embodiment, if it is assumed that the input voltage of the charger includes 110V and 220V, the minimum voltage is 110V. Of course, this is only exemplary, and there may be more or fewer types of voltages according to countries or regions, and the smallest voltage may be used as the input voltage of the charger. When charging starts, the input voltage of the charger can be directly measured in the OBC controller. In some cases, the input current can be directly measured in the OBC controller, and in this case, a method of estimating the input voltage based on whether the input current is greater than or less than a threshold can be applied.

[0044] In addition, according to an aspect of the embodiment, the input current may be estimated by the CP duty ratio. For this goal, a reference table (or map) indicating the correspondence between the CP duty ratio and the input current can be used. The reference table can be stored in the OBC controller in advance.

[0045] In addition, according to an aspect of the embodiment, the charging start time may be calculated by subtracting the predetermined margin and the estimated charging time from the departure time. Here, the estimated charging time can be calculated by dividing the battery capacity by the value obtained by multiplying the input voltage, the input current, and the charging efficiency of the OBC controller.

[0046] According to an aspect of the embodiment, after the charging start time is set based on the assumption of a low voltage (for example, 110V), charging may be started at the charging start time. At this time, when the sensed voltage is a high voltage (for example, 220V), the OBC controller may recalculate the charging time based on the high voltage. At this time, if it is determined that it can be fully charged when charging is started when the cheap electricity price is applied until the prescribed departure time, the OBC controller may reset the charging start time to the time when the cheap electricity price starts or a time thereafter. In this case, in order to reduce the charging cost, the OBC controller can perform low-load charging until the reset charging start time, and when the reset charging start time is reached, the normal load charging is started.

[0047] FIG. 3 shows a flowchart of a charging control method according to this embodiment.

[0048] FIG. 3 is a flowchart showing an example of an effective charging control process in a vehicle according to an embodiment of the present invention. In Figure 3, it is assumed that the minimum value of the input voltage is 110V, and the maximum value of the input voltage is 220V.

[0049] Referring to FIG. 3, first, the departure time can be input by the driver, and scheduled charging using cheap electricity prices can be set (S310).

[0050] The OBC controller may calculate the charging start time based on the assumption that the input voltage of the charger is 110V (S320). Here, the current SOC of the battery can be considered.

[0051] The OBC controller may stand by in the sleep mode until the charging start time, and wake up at the charging start time (S330) to start charging and measure the input voltage (S340). When the input voltage is 110V, the OBC controller can start charging without changing (S350). When the charging ends (S360), the vehicle may be switched to the IG off state (S370).

[0052] The failure reporting procedure S380 executed when the charging fails may be similar to the step S260 of FIG. 2, and therefore, a detailed description thereof will be omitted.

[0053] If the input voltage is not 110V (for example, 220V), the OBC controller can use the input voltage and the current estimated by the CP duty cycle to obtain the charging power, and use the charging power to recalculate and reset the charging start Start time (S341). At this time, as described above, when recalculating the charging start time, the time for applying cheap electricity prices can be considered.

[0054] When the charging start time is reset, the OBC controller may stand by while performing low-load charging until the reset charging start time (S342), and then, when the reset charging start time is reached, Normal charging is started (S350).

[0055] Next, a process of performing charging when the above-described charging control method is applied will be described with reference to FIG. 4.

[0056] FIGS. 4A and 4B are views showing an example of a process of performing charging according to an input voltage when a charging control method according to an embodiment of the present invention is applied.

[0057] In FIG. 4A, it can be assumed that the actual input voltage of the charger is 110V.

[0058] Referring to FIG. 4A, when the connector of the charger is connected and the departure time and cheap electricity price are set, the OBC controller can be based on

The charging start time is determined on the assumption that the input voltage is 110V. At this time, if the estimated charging time 2 is sufficiently included in the time period 2+3 minus the margin before the departure time 3 from the time period when the electricity price is cheap, then the OBC controller can determine the charging start time to be in During the time when electricity prices are cheap. The OBC controller in the sleep mode during the period 1 before the charging start time can start charging when the charging start time is reached. If the estimated voltage is equal to the actual voltage, charging can begin immediately.

[0059] In FIG. 4B, it can be assumed that the actual voltage of the charger is 220V.

[0060] Referring to FIG. 4B, when the connector of the charger is connected and the departure time and cheap electricity price are set, the OBC controller may determine the charging start time based on the assumption that the input voltage is 110V. At this time, if considering the margin 4 before the departure time, the estimated charging time 2+3 is not included in the time period 3+4 where the electricity price is cheap, then the OBC controller can take the departure time and the margin into consideration and change The charging start time is set to the time before the electricity price becomes cheaper. The OBC controller that is in sleep mode in the period 1) before the charging start time can start charging when the charging start time is reached. If the estimated voltage and the actual voltage are different, the actual voltage and the current estimated by the CP duty cycle can be used to reset the charging start time. After that, low-load charging can be performed in the remaining time period 2 until the reset charging start time. When the charging start time is reached, the OBC controller can start charging.

[0061] A common OBC controller may include: a booster (BS), which can be used as an input terminal; and a zero voltage switching (ZVS) full-bridge PWM circuit, which can be used as an output terminal; Control and implement with fewer components. However, in some cases, the ZVS at the output may fail during low-load charging, causing switching losses, and under certain circumstances, the OBC operation will be stopped. This will cause deterioration of charging efficiency.

[0062] In another embodiment of the present invention, if the low-load charging is performed according to the resetting of the charging start time, a method of only turning off the output terminal of the OBC controller during the low-load charging period may be implemented. That is, when the charging start time calculated for the first time is reached, the charger can supply power to the input terminal of the OBC controller, but can turn off the output terminal of the OBC controller until the reset charging start time, so as to enable The battery is not actually charged.

[0063] A flowchart of this operation is shown in FIG. 5.

[0064] FIG. 5 is a flowchart showing an example of an effective charging process in a vehicle according to an embodiment of the present invention.

[0065] In FIG. 5, it can be assumed that the minimum value of the input voltage is 110V, and the maximum value of the input voltage is 220V. Except for step S342', FIG. 5 is similar to FIG. 3, and repeated descriptions of similar steps will be omitted for clarity.

[0066] Referring to FIG. 5, when the charging start time is reset due to the difference between the estimated input voltage and the actual input voltage (S341), the OBC controller may turn off the output terminal until the reset charging start time (S341). S342'). When the reset charging start time is reached, the OBC controller may activate the output terminal (turn on) to start charging (S350).

[0067] According to the above-mentioned embodiment of the present invention, the charging cost can be reduced by making the best use of the scheduled charging function by considering the departure time and cheap electricity prices. In addition, by estimating the charging time based on actual measurement, the success rate of full charging can be improved, so that cheap electricity prices can be optimally used, and uniform charging regardless of the type of charger (input voltage/country/method) logic. If the output terminal of the OBC controller is temporarily turned off, the energy loss caused by the stop of the OBC operation during low-load charging can be reduced, and the durability of the OBC controller can be improved.

[0068] In the above embodiment, when the charging start time calculated for the first time is reached, in order to actually measure the input voltage of the charger, the OBC controller may be operated to perform charging. Therefore, if a difference occurs frequently between the estimated input voltage and the actually measured input voltage, the relay will be frequently used according to the configuration of the OBC controller, and thus the lifespan of the power element may be reduced.

[0069] Therefore, in another embodiment of the present invention, a method for measuring input power without performing actual charging is proposed.

Pressure, and can more accurately estimate the input current method.

[0070] According to an aspect of the embodiment, the internal switch of the OBC controller can be used to measure the input voltage without actual charging. If charging is performed using a charger (specifically, EVSE) that does not supply power when connected to the connector, power can be supplied to the vehicle when the internal switch is turned on. Representative examples of such switches include "S2" switches. The position of the S2 switch will be described with reference to FIG. 6.

[0071] FIG. 6 is a view showing switches set on the side of the OBC controller applied to the embodiment of the present invention.

6, the charger (EVSE) 200 may include an S1 switch 610, and the vehicle-side OBC controller 100 may include an S2 switch 620. When the S2 switch 620 is turned on/off, the resistance of the closed circuit formed between the EVSE 200 and the OBC controller 120 will change. That is, when the S2 switch 620 is open, the equivalent resistance of the closed circuit (hereinafter, referred to as "CP circuit" for convenience) can become R1+R3, and when the S2 switch is closed, R2 and R3 can be connected in parallel To change the equivalent resistance. Such a resistance change will change the CP voltage measured at the R1 terminal 630 of the EVSE. When the voltage changes, the S1 switch 610 of the EVSE 200 is operable to transmit power to the OBC controller 120.

[0073] The OBC controller may include: a rectifier located on the input side; a power factor correction circuit located on the intermediate side; and a DC/DC converter located on the output side. In the CP circuit, when the S2 switch is closed, the resistance of the vehicle-side circuit will change, and the CP voltage measured in the EVSE will change, so that the charger can output a changed voltage. At this time, the voltage can be applied to the input side (ie, rectifier) of the OBC controller, and can be measured to confirm the input voltage of the OBC controller. Therefore, the input voltage can be measured by turning on the S2 switch when the OBC controller is not performing a charging operation.

[0074] Therefore, when the closed circuit formed between the charger and the OBC controller is turned on, the S2 switch will change the equivalent resistance of the vehicle, thereby changing the voltage measured in the charger, so that the charger starts to supply power to the vehicle. . Since the on/off state of the switch does not change (or reset) the state related to the payment in an ordinary charger (EVSE), even if the switch is turned on to verify the input voltage, and then turned off, charging The payment status of the device may not change. Therefore, the user does not need to inconveniently input charging-related settings to the charger again.

[0075] FIG. 7 shows the structure of the OBC controller and the input voltage measurement according to the turning on of the S2 switch.

[0076] FIG. 7 is a circuit diagram showing a vehicle-side charger structure and a method of measuring an input voltage using a switch according to an embodiment of the present invention.

7, the OBC controller may include: a rectifier 710, which is located on the input side; a power correction factor circuit 720, which is located on the middle side; and a DC/DC converter 730, which is located on the output side. When only the S2 switch is operated, that is, when the charging operation is not performed, as indicated by the upward arrow 740, the power flow may be limited to the rectifier. In this process, since the input voltage can be applied to the capacitor 711 of the rectifier 710, the actual input voltage can be obtained by measuring the voltage applied to the capacitor.

[0078] When performing ordinary charging, as indicated by the downward arrow 750, power may be transmitted to the output side, and the actual input voltage may be measured using the method of measuring Vo 731.

[0079] Even if the S2 switch is used to measure the input voltage, it is difficult to measure the input current. Therefore, the CP duty cycle can be used to estimate the input current. In an embodiment, a method of estimating an input current for improving the buffering probability will be described with reference to FIGS. 8A and 8B.

[0080] FIGS. 8A and 8B are views illustrating an input current estimation method according to an embodiment of the present invention.

[0081] Referring to FIG. 8A, the correspondence relationship between the CP duty cycle and the input current can be predefined or represented in the form of a graph. The OBC controller can use the detected CP duty cycle to estimate the input current by referring to the corresponding graph or table/map.

[0082] In order to improve the buffering probability, the input current value can be made low within a reasonable range. Therefore, in the embodiment, as shown in FIG. 8B, the maximum power P of the charger can be used_IN MAX _CHARGERAnd the maximum power of the OBC controller P_IN Divide by the measured input voltage V of the OBC controller_{AC RMS LPF}Obtained value, and use CP duty cycle D_{CP Duty}Estimated current I_BSThe smallest value in I_{RMS FINAL}To calculate the estimated charging time.

[0083] In addition, as shown in FIGS. 9A to 9c, the estimated charging time may be used to determine the charging start time. 9A to 9c are views showing examples of logic for determining an estimated charging time according to an embodiment of the present invention.

[0084] Referring to FIG. 9A, it can be considered that the vehicle departure time minus the estimated charging time T_{chargingEST1MATED}And the predetermined margin T_marginThe time obtained, and the time when the cheap electricity price starts to determine the charging start time. More specifically, as shown in FIG. 9B, when the vehicle departure time minus the estimated charging time T_{charging EST1MATED}And the predetermined margin T_marginWhen the obtained time is earlier than the time when the cheap electricity price is applied, the charging start time may be set to the time before the cheap electricity price starts. For comparison, as shown in Figure 9c, when the estimated charging time T is subtracted from the vehicle departure time_{charging EST1MATED}And the predetermined margin T_marginWhen the obtained time is later than the time when the cheap electricity price is applied, the charging start time may be set to the time when the cheap electricity price starts.

[0085] FIG. 10 illustrates a charging control method according to this embodiment. Fig. 10 is a flowchart showing an example of an effective charging control process in a vehicle according to an embodiment of the present invention.

[0086] Referring to FIG. 10, first, the departure time can be input by the driver, and the scheduled charging can be set using cheap electricity prices (S1010).

[0087] The OBC controller may measure the input voltage applied to the input side of the OBC controller by turning on the S2 switch (S1020A). At this time, since the OBC controller can only turn on the S2 switch without activating the charging function, the power will not be output to the BMS through the middle and output sides of the OBC controller.

[0088] In addition, the OBC controller may use the CP duty cycle to estimate the input current (1020B), and the process described with reference to FIG. 8 may be applied here.

[0089] After both the voltage measurement and the current estimation are finished, the charging start time is set (S1030), and the process described with reference to FIG. 9 can be applied here.

[0090] After the charging start time is set, the OBC controller can turn off the S2 switch, so as to operate in the sleep state (ie, IG off) until the charging start time (S1040), and then at the start of charging Time to wake up (S1050) to start charging (S1060).

[0091] When the charging ends (S1070), the vehicle can be converted to the IG off state (S1070). The failure reporting procedure S1090 executed when the charging fails is similar to the step S260 described with reference to FIG. 2, so the detailed description thereof will be omitted.

[0092] According to the above-mentioned embodiment of the present invention, since no other charging process is performed before the final charging operation, the robustness of the relay can be ensured and the life of the power element can be prevented from being damaged.

[0093] In addition, since the charging time is estimated more stably, it is possible to increase the probability of full charging while maximizing the use of cheap electricity prices. In addition, in a normal charging control method, after charging starts, the vehicle cannot be switched to the IG off state. This is because when the vehicle is switched to the IG off state, the payment status of the charger will be reset, so the driver will pay again. However, when the S2 switch is turned on/off, the payment status of the charger will not change. Therefore, charging can be performed without repayment, and the vehicle can be switched to the IG off state before starting charging. Therefore, the efficiency of scheduled charging can be improved.

[0094] The present invention can be implemented as code that can be written in or embodied by a computer-readable recording medium, so it can be read by a processor. The computer-readable recording medium may be any type of recording device that can store data in a computer-readable manner. Examples of the computer-readable recording medium include: hard disk drive (HDD), solid-state drive

(SSD), Silicon Disk Drive (SDD), ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and carrier wave (for example, data transmission on the Internet).

[0095] The above detailed description should not be construed as limiting the present invention in all aspects, and should be considered as merely exemplary. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all equivalent modifications made without departing from the present invention should be included in the appended claims.